Let ω denote the space-time vector of the first kind
(u/√(1 - u²}), i/√(1 - u²))
(u = velocity of matter),
F the space-time vector of the second kind (M,-iE)
(M = magnetic induction, E = Electric force,
f the space-time vector of the second kind (m,-ie)
(m = magnetic force, e = Electric Induction.
s the space-time vector of the first kind (C, iρ)
(ρ = electrical space-density, C - ρu = conductivity current,
ε = dielectric constant, μ = magnetic permeability,